Halogenated flame retardant polyols made by reaction of a halogen containing cyclic acid anhydride, a polyol and an epoxide are described in Versnel U.S. Pat. No. 3,455,886. Preparation of such compounds using tetrabromophthalic anhydride as the cyclic acid anhydride is set forth in Pape et al, "J. Cellular Plastic", Nov. 1968, p. 438-442. Use of magnesium oxide and sodium acetate to neutralize the residual sulfuric acid is described. Although both magnesium oxide and sodium acetate have been found to be effective neutralizing agents, they unfortunately result in the formation of a hazy product which is objectionably from a commercial view point. Thus a need exists for a means of neutralizing the reaction product to form a commercially acceptable haze-free reactive flame retardant.